After leveling off at about 50 percent usage share late last year, Microsoft’s Internet Explorer has been on an upward trend, thwarting early attempts to write the browser’s obituary. In March, overall usage in IE grew yet again, and while the gains are minor, they come at the expense of Google Chrome and Mozilla Firefox, both of which have–gasp–dropped off in recent months.

“We continue to see great strides made against our core metric: IE9 share on Windows 7,” he writes. “This month in the US nearly 50 percent of Windows 7 users are experiencing the best the web has to offer with IE9.” According to the Net Applications numbers published by Microsoft, IE 9 is responsible for 48.8 percent of US-based web traffic from Windows 7, compared to 14.6 percent for Google Chrome and 11.6 percent for Mozilla Firefox.

Looking at the worldwide figures, IE 9 still has a commanding lead: 34.5 percent compared to 21.2 percent for Chrome and 13.3 percent for Firefox.

“Internet Explorer has reached an inflection point,” a Microsoft representative told me. “This month we launched our television ad and set-up a fun Tumblr site to showcase just how far IE has come. We are starting to see the results of a revitalized Internet Explorer, a brand that has gotten its groove back … it is clear that a shift is occurring.”

Indeed, in just the first three months of 2012, IE has grown from 51.87 percent usage share to 53.8 percent, growth of about 2 percentage points. Meanwhile, usage in both Chrome and Firefox has fallen in that same time frame by about a half percentage point each. Before the start of 2012, IE had been on a lengthy and slow downward trend.